Self-propelled means for scaffolds



June 21, 1966 G. T. WARTHEN 3,256,954

SELF-PROPELLED MEANS FOR SCAFFOLDS Filed March 31, 1965 I I I2 "I i w a: I al I I I /6 INVENTOR.

65am: [Mien/EN BY 6 Mg ATTORNEYS.

United States Patent Office Patented June 21, 1966 SELF-PROPELLED MEANS FOR SCAFFOLDS George-Thomas War-then, Emmitsburg, Md., assignor of one-fourth each to William H. Brown, Takoma Park,

Md., and Robert A. Warthen and Charles P. Warthen,

both of Emmitsburg, Md.

Filed Mar. 31, 1965, Ser. No. 444,348 2 Claims. (Cl. 182-13) The present invention is a continuation-in-part of my US. application Serial No. 351,627, filed March 13, 1964.

The present invention relates to a self-propelled means for scaffolds and more particularly-to a guidable and selfpropelled unit which may be attached thereto.

In accordance with the present invention, a self-propelled scaffold means is provided comprising spaced upright standards which support a working platform and guide means and a propelling unit that can be attached to the scaffold and which guide means and propelling unit consist of an integral or single unit.

It is another object of the present invention to provide a guide and propulsion unit that can be readily attached to conventional scaffold means now in the field, in an inexpensive and simple manner.

A further object of the present invention is to provide a novel self-propelled scaffold means provided with a single upright member that carries guide means and a propulsion unit for attachment to the standard type of scaffold used today.

Various other objects and advantages of the present in-- vention will be readily apparent from the following detailed description when considered in connection with the accompanying drawing forming a part hereof and in which:

FIGURE 1 is a side elevational View of the self-propelled scaffold means of the present invention;

FIGURE 2 is a view of the invention looking at it from the front;

FIGURE 3 is an enlarged view taken along the line 3-3 of FIGURE 2;

FIGURE 4 is a view taken along the line 44 of FIG- URE 2, and 6 FIGURE is a detailed view of the cross-section of the steering handle connected to the guide tube means.

Referring now to the drawing, wherein like reference characters designate like elements throughout the several views thereof, reference numeral 10 generally designates a scaffold consisting of vertical spaced apart iron standards or members 12 which have secured thereto by any suitable means a horizontal working platform 14. As shown, two of the vertical members 12 are spaced adjacent the front end of platform 14 and two are spaced adjacent the rearward end thereof, with all standards 12 being provided with caster members 16 secured to the bottom thereof by any suitable means thus providing a scaffold which may be moved about by workmen. Secured transversely between the forward and rearward pair of vertical members 12 by any suitable means is a series of transverse or cross members 18. As is apparent, cross members 18 may be disposed vertically of each other at any suitable interval.

In accordance with the present invention, scaffold 10 is provided with a guidable and self-propelled unit indicated generally at 20. Guide and power unit 20 comprises a vertical cylindrical steering rod 22 having a wheel fork 24 secured to its lower end with a wheel axle 26 extending thereacross and carrying a drive Wheel 28 which also acts as a guide wheel as more fully explained hereinafter. A motor platform 30 is secured to the top of fork 24 and has mounted thereon a conventional reversible electric motor 32. Axle 26 fixedly carries a pulley 34 while motor 32 has fixedly mounted thereon a drive pulley 36 so that power is transmitted from motor 32 to drive wheel 28 by means of a tension belt 38 mounted on pulleys 34 and 36.

The upper end of power unit 20 is provided with an enlarged cylindrical sleeve indicated generally at 40 which prevents, by any suitable means, such as coacting annular flanges on arm 22 and sleeve 40, the inadvertent separation of arm 22 and sleeve 40. Cylindrical sleeve 40 has a first rectangular plate 42 secured adjacent the lower end thereof with a second rectangular plate 44 being aflixed adjacent its upper end. Plate 42 is provided with a series of vertically spaced apertures on each side of sleeve 40 as shown in FIGURE 2 in order to receive bolt 42' for adjustably holding a first Z-shaped bracket 43. Plate 44 is provided with a substantially vertical elongated slot on each side of sleeve 40 as shown in FIGURE 2 in order to receive a wing nut 48 for securing thereto a second Z-shaped bracket 46 as best shown in FIGURE 4. There is thus provided a means for vertically adjusting power unit 20 so that traction wheel 28 may effectively engage the surface to be traversed.

Cylindrical sleeve 40 is provided with a lower sleeve -or bush bearing 50 for journalling steering rod 22 therein, and an upper bushing 52 consisting of a cap member with an opening in the top thereof to receive a lower square end 54 of an L-shaped steering handle 56. Bearing numbers 50 and 52 may be secured to sleeve 40 in any suitable manner. A biasing spring 58 is disposed within cylindrical sleeve 40 and bears against the top of upper bearing 52. A threaded annular cap 60 is threaded on the upper end of sleeve 40 with steering handle 56 extending therethrough into a conveniently provided,

slot in the upper end of rod 22 so that the movement or rotation of handle 56 will cause rod 22 and wheel 28 to be turned therewith.

One of the front standard members 12 carries an electric motor control means 62 which is connected to electric motor 32 by a conventional electrical cable generally indicated at 64. I

In operation an operator controls electric motor 32 by control means 62 so as to drive it in either direction propelling scaffold 10 to the desired location. It will also be observed that wheel 28 may be readily turned by an operator by manipulating handle 56 so that scaffold 10 may be guided and propelled by the same power unit 20. Power 20 may be detached from scaffold 10 by loosening bolts 42, 48 thus releasing cross members 18 from their respective braces 43, 46.

From the foregoing, it will now be seen that-there is herein provided a self-propelled scaffold, which accomplishes all of the objects of this invention and others, including many advantages of great practical utility and commercial importance.

As many embodiments may be made Within this inventive concept, and as many modifications may be made in the embodiment herebefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

I claim:

1. In combination with a scaffold comprised of spaced front and rear uprights, a working platform supported by said uprights, a caster wheel at the base of each upright; and upper and lower transverse cross members extending between said front uprights; a detachable guide and power unit including a cylindrical sleeve; upper and lower plates secured to said sleeve; spaced series of open ings in each of said upper and lower plates; brackets selectively attachable in selected openings of each series for engagement with said upper and lower transverse members respectively; a steering rod extending through said sleeve, a steering handle on the upper end of said rod adjacent said working platform; means precluding vertical disengagement of said rod and said cylinder; a steering fork carried by the lower end of said steering rod; an axle extending transversely across said fork, a steering and power Wheel mounted on said axle; a platform carried by said fork; a motor mounted on said platform and having a drive shaft; a belt and pulley connection between said drive shaft and said axle; and means for supplying electric current to said motor.

2. The structure of claim 1 wherein said means precluding vertical disengagement of said steering rod from said cylinder comprise an apertured end cap on said cylinder through which said rod extends, a flange on said rod interiorly of said cylinder, and a compression spring positioned between said end cap and said flange.

References Cited by the Examiner UNITED STATES PATENTS 10/1943 Droeger 182-119 1/1950 Duke 18011 10/1950 Schlessman 182-16 3/1959 La Plante 182121 X 11/1963 Langer 18263 X FOREIGN PATENTS 2/1960 France.

CHARLES E. OCONNELL, Primary Examiner.

REINALDO P. MACHADO, Examiner. 

1. IN COMBINATION WITH A SCAFFOLD COMPRISING A SPACED FRONT AND REAR UPRIGHTS, A WORKING PLATFORM SUPPORTED BY SAID UPRIGHTS, A CASTER WHEEL AT THE BASE OF EACH UPRIGHT; AND UPPER AND LOWER TRANSVERSE CROSS MEMBERS EXTENDING BETWEEN SAID FRONT UPRIGHTS; A DETACHABLE GUIDE AND POWER UNIT INCLUDING A CYLINDRICAL SLEEVE; UPPER AND LOWER PLATES SECURED TO SAID SLEEVE; SPACED SERIES OF OPENING IN EACH SAID UPPER AND LOWER PLATES; BRACKETS SELECTIVELY ATTACHABLE IN SELECTED OPENINGS OF EACH SERIES FOR ENGAGEMENT WITH SAID UPPER AND LOWER TRANSVERSE MEMBERS RESPECTIVELY; A STEERING ROD EXTENDING THROUGH SAID SLEEVE, A STEERING HANDLE ON THE UPPER END OF SAID ROD ADJACENT SAID WORKING PLATFORM; MEANS PRECLUDING VERTICAL DISENGAGEMENT OF SAID ROD AND SAID CYLINDER; A STEERING FORK CARRIED BY THE LOWER END OF SAID STEERING ROD; AND AXLE EXTENDING TRANSVERSELY ACROSS SAID FORK, A STEERING AND POWER WHEEL MOUNTED ON SAID AXLE; A PLATFORM CARRIED BY SAID FORK; A MOTOR MOUNTED ON SAID PLATFORM AND HAVING A DRIVE SHAFT; A BELT AND PULLEY CONNECTION BETWEEN SAID DRIVE SHAFT AND SAID AXLE; AND MEANS FOR SUPPLYING ELECTRIC CURRENT TO SAID MOTOR. 